His medical history included diabetes but his doctor recommended Harris for the study and deemed him healthy enough to participate, Lewis said.

As part of the sleep study, a camera was present in the room to monitor Harris' sleep. Lewis, the only family member who has seen the video, said it appeared that his nephew was waving multiple times in distress, getting no response.

"We saw him sit up just a little bit enough to wave his hand in some type of, I'm saying distressed but there was no audio," he said.

Lewis said he watched Harris wave his hand six or seven different times. He said he believes the medical staff at the center waited too long to help his nephew.

"I just can't describe, you know, the pain to know what a wonderful young man he was, how tender and loving he was to just not get the care that he needed at that time," he said.

In a written statement released Monday, Emory Healthcare officials said, "At all times during the sleep study, Mr. Harris was monitored and the providers appropriately attended to him."

He died of sudden cardiac arrest, according to the statement from Emory Healthcare, which is the largest health care system in Georgia.

Emory declined to answer questions or comment further on the specific care for Harris or the allegations surrounding his death.

The man's mother has hired an attorney.

Final Hours Caught on Video

Lewis described in detail the images he said he saw on the video taken the day of his nephew's death. He said it was difficult to watch.

"I mean, since he was 4 days old, he was just my boy and then to actually see him die like that was just all I can do," he said. "But I sat through it because I knew my sister wouldn't be able to and she asked that I would and that was the least I could do ... to see what actually happened".

Lewis said, in the video, after waving several times with no response, Brandon was able to move around enough to get to the end of the bed, sit up and briefly disconnect himself from the apparatus to which he was attached.

"Once that happened, this woman comes to the door and she finally comes over to his bed and he tells her I guess that he's having some problems and needs to go to the restroom ..."

Lewis said the woman leaves while, he assumes, Harris went to the restroom. He said she returns and tries to get Harris to go back to the bed.

"Obviously, he tells her no, that he's more comfortable standing up," Lewis said.

Lewis said that at some point on the video footage, two other people come in the room. He said Harris appeared to be having breathing problems and the people in the room appeared to be consoling him.

"At one point, he leans to his right and sort of eases his knee down to the floor and he collapses. ... I believe at that point -- I can't say definitively -- but I believe at that point he was dead," Lewis said.

He said he saw in the video that the people in the room did not give him Harris CPR or check for any vital signs.

Community Calls for Investigation

The family, community leaders and activists are calling for Emory to shut down its sleep center until a thorough investigation of Harris' death is conducted.

They delivered a letter to Emory's chief medical officer Monday calling for the center's closure and demanding that a copy of the video showing what happened to Harris in the time before his death be made available to both the family and the public.

State Sen. Vincent Fort expressed support for such efforts.

"They need to shut it [the center] down, have a thorough review of all the procedures and not open it until they can assure the public that it's being run the right way," he said.

In the statement, Emory said it "continues to express sympathy to the family of Mr. Harris" but it has no plans to release the video. "Emory cannot release the video recording of the sleep study because it must be viewed on special software that can only be seen in the sleep lab, where there are ongoing studies."

In the meantime, Fort said, he urged the public not to participate in any studies there.

"I would just tell the public if you're going to go over there, you need to think twice," he said. "If your physician or someone else assigns you or gets a referral over there, think twice before you go over there because what happened to Brandon could very well happen to them."

Michael Langford, a community activist with the United Youth-Adult Conference, has been heavily involved in the family's efforts. He said they have one goal in mind.

"Our goal is not to embarrass Emory but to make sure the public's safety is priority number one," Langford said.

Sudden Cardiac Arrest Apparent Cause of Death

The statement from Emory said the cause of Harris' death was sudden cardiac arrest. "Mr. Harris died because of 'sudden cardiac death,' meaning that his heart stopped suddenly and without warning," the statement said.

Officials from the Dekalb County Medical Examiner's Office said they conducted a medical examiners inquiry on the case and based on that inquiry, there was no need for further investigation.

"He had a medical history that could explain a sudden death," Paul Kelhofer, director of the Dekalb County Medical Examiner's Office, said.

A Family Remembers

Lewis said he hopes people remember his nephew, a medical assistant with hopes of one day working for Emory, for his warm, effervescent personality.

Family members have started a children's youth program in Atlanta in Brandon's name, he said.

"Brandon was a very humble young man," he said. "But at the same time, he was very outgoing, very caring. He just loved life."